diff --git a/pycapo/models.py b/pycapo/models.py
index c0382ff6d75d3afa57ee732f10ded6093b53fcbe..1e71d606b0919f8d1d15560bd12ad7ccb3caccee 100644
--- a/pycapo/models.py
+++ b/pycapo/models.py
@@ -46,7 +46,7 @@ class CapoConfig:
         elif 'CAPO_PROFILE' in os.environ:
             self.profile = os.environ['CAPO_PROFILE']
         else:
-            raise ValueError('could not determine profile')
+            raise ValueError('Expected profile via CAPO_PROFILE or \"profile\" kwarg, found neither')
 
         if 'path' in kwargs and kwargs['path']:
             self._path = kwargs['path']